Flat panel displays using liquid crystal display (LCD) technology are widely known and have found application in a number of fields for displaying visual information. In a flat panel LCD, the screen area, which is substantially rectangular, is divided into a large number of individual color dots. Each set of color dots is capable of displaying a full color gamut. It is known for the sets to comprise a three-dot combination of red, green and blue, a four-dot combination of red, green, green and blue, a four-dot combination of red, green, blue and white, and a six-dot combination of red, green, blue, yellow, cyan and magenta, as well as other combinations that allow a full color display. In an active matrix flat panel LCD, each color dot contains a transistor switch. A liquid crystal fluid, contained between a front plate and a rear plate, is twisted by a voltage which changes the axis of polarization of light, allowing the individual color dots to transmit or block light passing from a backlight source through the individual color filters. The color dots are arranged in a grid comprising rows and columns, and there can be several hundred or thousand vertical columns of color dots going across the display as well as hundreds or thousands of horizontal rows of color dots, resulting in most cases in more than 1,000,000 individual color dots. Each color dot has a vertical column and horizontal row grid address and is driven by electrical impulses fed along its respective row from a bus located on one of the side edges of the flat panel LCD and along its respective column from a top or bottom edge of the flat panel LCD. In general, the horizontal row drivers are referred to as gate drivers and the vertical column drivers are referred to as source drivers, but these may be reversed in practice, as will be known to those of skill in the art. In either case, the source driver signal provides the gray scale data for a given color dot, while the gate driver signal changes a given line of thin film transistors (“TFTs”) from “off” to “on” for a given “line time.” This signal from the gate driver thereby allows the charging of a capacitor associated with the individual color dot, determining the voltage held by the color dot for an entire frame period.
During the manufacture of a flat panel LCD, the panel that comprises the liquid crystal fluid and the front and rear plates contains flexible printed circuit elements that function as input and output for the gate, source, and heater driver circuit card assemblies. These circuit elements, or “tabs,” contain electrical contacts, or “pads,” that must be properly aligned with matching electrical contacts on each respective driver circuit card assembly in order for all the color dots to receive electrical signals and respond properly. An anisotropic, electrically conductive adhesive is typically used to make the electrical connection between the pads on the tabs of the LCD and the pads on each driver circuit card assembly, or “driver.” Alignment is key, as misalignment can result in a LCD display where parts of the screen are either partially or completely unresponsive to electrical signals, and is unsuitable for sale. Furthermore, because LCD tabs are very fragile the process of aligning a tab with a driver can damage an LCD if the tabs are allowed to flex, shift, or rub against the drivers or other surfaces during the alignment process.
U.S. patent application Ser. No. 12/056,849 discloses a retractable pin tool device and method that may be used in the manufacture of flat panel display devices. This application hereby incorporates U.S. patent application Ser. No. 12/056,849 by reference in its entirety. An exemplary embodiment of the retractable pin tool device of said application enables alignment of an LCD panel with adhered tabs with driver circuit card assemblies. The known art has yet to provide a carrier for protecting, transporting, etc. an LCD with adhered tabs that have been aligned upon a driver where said carrier is also capable of providing a work surface during various steps of the manufacturing process.
An exemplary embodiment includes a transportable carrier for an LCD with adhered tabs that have been aligned upon a driver. In a preferred exemplary embodiment, a first carrier section is placed about a retractable pin tool. To ensure proper alignment of the carrier about the tool, the pin tool device may be equipped with two pins that match up with corresponding reciprocals on the first carrier section. In this preferred exemplary embodiment, an LCD with adhered tabs may be placed in the first carrier section after the carrier section has been positioned about a retractable pin tool and then work can be performed to bond the tabs of the LCD to paths on drivers that have also been positioned within the first carrier section. Subsequently, once the work being performed on the LCD and its corresponding components has reached a stopping point, a second carrier section may be positioned over the first carrier section and then secured to the first carrier section via a closing means. In a preferred exemplary embodiment, the first and second carrier sections are clamped together such that they then form a single unit which encases an LCD and its components that were being processed. The single unit carrier comprising the first and second carrier sections may then be removed from its position about a retractable pin tool so that it may be stored safely until the next time work is to be performed on the contents of the carrier.
Exemplary embodiments may comprise a transportable carrier that also provides a work surface while tabs attached to an LCD are being aligned upon a driver. In a preferred exemplary embodiment, the transportable carrier device comprises a first carrier section formed of a machined, phonetic material that will not hold an electric charge. In another exemplary embodiment, the transportable carrier may assist in the use of a retractable pin tool by providing additional support to the tool and by keeping various components that are being worked on level with certain portions of the pin tool. Other exemplary embodiments may provide a means of storing an LCD, the tabs attached to the LCD, the drivers, and various other components during times the unit is not being worked on such that the LCD and the other components are protected. In some embodiments, the transportable carrier device may be further used as an alignment tool that enables more accurate positioning of parts onto the LCD by the retractable pin tool.